SiO2@Gd2O3:Yb3+, Ln3+ (Ln=Er, Tm, Ho)核壳微球的制备及上转换发光性能

Preparation and upconversion luminescence properties of SiO2@Gd2O3:Yb3+, Ln3+ (Ln=Er, Tm, Ho) core-shell microspheres

  • 摘要: 为了解决稀土掺杂上转换发光材料价格昂贵且粒径可控性差的问题,采用简单的化学沉淀法以价格低廉且易制备的SiO2微球为核,在其表面均匀包覆了Gd2O3:Yb3+, Ln3+(Ln=Er, Tm, Ho)壳层,成功合成了球形SiO2@Gd2O3:Yb3+, Ln3+(Ln=Er, Tm, Ho)核壳上转换发光材料。XRD结果表明,尿素作为沉淀剂优先与稀土离子反应得到SiO2@Gd(OH)CO3:Yb3+, Ln3+前驱体,经800℃煅烧后壳层进一步转化成结晶性良好的立方相Gd2O3:Yb3+, Ln3+。SEM和尺寸分布图表明,所制备样品为理想的核壳微球形貌,尺寸均匀,平均粒径约为580 nm。在980 nm激光激发下,SiO2@Gd2O3:Yb3+, Ln3+(Ln=Er, Tm, Ho)核壳微球分别表现出红光、蓝光、绿光发射,对应于Er3+4F9/24I15/2跃迁、Tm3+1G43H6跃迁及Ho3+5S25I8跃迁,与色度图色坐标发光颜色区域相一致,说明通过简单的调节SiO2@Gd2O3:Yb3+, Ln3+核壳微球中壳层掺杂的稀土离子种类,成功实现了三色上转换发光。

     

    Abstract: In order to solve the problem of high price and poor size controllability of rare earth doped upconversion luminescent materials, spherical SiO2@Gd2O3:Yb3+, Ln3+ (Ln=Er, Tm, Ho) core-shell upconversion luminescent materials were successfully synthesized by simple chemical precipitation method using low cost and easy to prepare SiO2 microspheres as cores and uniformly coated with Gd2O3:Yb3+, Ln3+ (Ln=Er, Tm, Ho) shells. XRD results show that the SiO2@Gd(OH)CO3:Yb3+, Ln3+ precursor is firstly obtained by the reaction of urea with rare earth ions, then the Gd(OH)CO3:Yb3+, Ln3+ shell is further transformed into cubic phase Gd2O3:Yb3+, Ln3+ with good crystallinity after calcination at 800℃. SEM and size distribution images show that the prepared samples are ideal core-shell microspheres with uniform size, and the average diameter is about 580 nm. Under the excitation of 980 nm, SiO2@Gd2O3:Yb3+, Ln3+ (Ln=Er, Tm, Ho) core-shell microspheres exhibit red, blue and green emissions respectively, corresponding to the 4F9/24I15/2 transition of Er3+, the 1G43H6 transition of Tm3+, and the 5S25I8 transition of Ho3+, which are consistent with the luminescence color region of chromaticity color coordinates, indicating that three color upconversion luminescence is successfully achieved by simply adjusting the doped rare-earth ion species in the shell of SiO2@Gd2O3:Yb3+, Ln3+ core-shell microspheres.

     

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